"Ophidia Ophidia (also known as Pan-Serpentes) is a group of squamate reptiles including modern snakes and all reptiles more closely related to snakes than to other living groups of lizards. Ophidia was defined as the ""most recent common ancestor of ""Pachyrhachis"" and Serpentes (modern snakes), and all its descendants"" by Lee and Caldwell (1998: 1551). The latter author has used Ophidia in a manner inconsistent with this definition, using it to incorporate other more basal stem-snakes, such as the Late Cretaceous ""Najash rioegrina"" or the Jurassic ""Diablophis"" and ""Portugalophis"". Modern snakes are thought to have evolved from either burrowing or"
"Ophidiiformes Ophidiiformes is an order of ray-finned fish that includes the cusk-eels (family Ophidiidae), pearlfishes (family Carapidae), viviparous brotulas (family Bythitidae), and others. Members of this order have small heads and long slender bodies. They have either smooth scales or no scales, a long dorsal fin and an anal fin that typically runs into the caudal fin. They mostly come from the tropics and subtropics, and live in both freshwater and marine habitats, including abyssal depths. They have adopted a range of feeding methods and lifestyles, including parasitism. The majority are egg-laying, but some are viviparous. This order includes a"
"Ophidiomorpha Ophidiomorpha is a clade composed of snakes and their primitive and early relatives proposed by Palci and Caldwell (2007) The clade was defined as a node-based clade containing the most recent common ancestor of dolichosaurs, adriosaurs, ""Aphanizocnemus"", and fossil and extant Ophidia and all of its descendants. The existence of Ophidiomorpha as a clade may become problematic as it is placed within the Pythonomorpha, a clade that itself is not universally agreed upon containing mosasaurs and snakes, their most recent common ancestor and all of its descendants. Indeed, most 20th-century herpetologists and paleontologists rejected this idea and sought instead"
"Opiliones The Opiliones ( or ; formerly Phalangida) are an order of arachnids colloquially known as harvestmen, harvesters or daddy longlegs. , over 6,650 species of harvestmen have been discovered worldwide, although the total number of extant species may exceed 10,000. The order Opiliones includes five suborders: Cyphophthalmi, Eupnoi, Dyspnoi, Laniatores, and the Tetrophthalmi which were named in 2014. Representatives of each extant suborder can be found on all continents except Antarctica. Well-preserved fossils have been found in the 400-million-year-old Rhynie cherts of Scotland, and 305-million-year-old rocks in France, which look surprisingly modern, indicating that their basic body shape developed"
"Ophidiasteridae The Ophidiasteridae (Greek ""ophidia"", Οφιδια, ""of snakes"", diminutive form) are a family of sea stars with about 30 genera. Occurring both in the Indo-Pacific and Atlantic Oceans, ophidiasterids are greatest in diversity in the Indo-Pacific. Many of the genera in this family exhibit brilliant colors and patterns, which sometimes can be attributed to aposematism and crypsis to protect themselves from predators. Some ophidiasterids possess remarkable powers of regeneration, enabling them to either reproduce asexually or to survive serious damage made by predators or forces of nature (an example for this is the genus ""Linckia""). Some species belonging to ""Linckia"","
"made up of embedded ossicles. The roughly 1900 extant species are placed in 230 genera, grouped in the three orders currently living: Oegophiurida, Phrynophiurida, and Ophiurida. Also, a Paleozoic order exists, the Stenurida. The relationships among ophiuroids and all other echinoderms provide an enduring problem in invertebrate evolution. Developmental and other studies based on modern organisms imply that asteroidea and ophiuroids are not closely related within the echinoderms. Stenurid morphology, in contrast, suggests a close common ancestry for the two; the nature of the ambulacral plates is important, but even their general form is transitional. This is a Paleozoic (Ordovician–Devonian)"
"Olbiaspididae Olbiaspididae is a family of extinct amphiaspidid heterostracan agnathans whose fossils are restricted to Lower Devonian marine strata of Siberia near the Taimyr Peninsula. In life, all amphiaspidids are thought to be benthic animals that lived most of their lives mostly buried in the sediment of a series of hypersaline lagoons. Amphiaspids are easily distinguished from other heterostracans in that all of the plates of the cephalothoracic armor are fused into a single, muff-like unit, so that the forebody of the living animal would have looked, in the case of olbiaspidids, vaguely like a hot water bottle with a"
"Tethytheria Tethytheria is a clade of mammals that includes the sirenians and proboscideans, as well as the extinct order Embrithopoda. Though there is strong anatomical and molecular support for the monophyly of Tethytheria, the interrelationships between the included taxa remain disputed. The tethytheres are united by several characters, including anteriorly facing orbits and more or less bilophodont cheek teeth (double transverse ridges on the crowns of the teeth). Proboscidea and Sirenia are linked together based on auditory characters in their petrosal bones, but this link may be a homoplasy. Desmostylians, traditionally considered tethytheres, have been tentatively assigned to Perissodactyla, along"
"Fieldia (animal) Fieldia is a genus of worm known from the Cambrian Burgess Shale, and assigned to the Priapulids. It was originally interpreted as an arthropod; its trunk bears a dense covering of spines, and its proboscis is small. It fed on sea-floor mud, evidenced by the frequent presence of sediments preserved in its gut. Along with the other Cambrian priapulids ""Ottoia"", ""Selkirkia, Louisella"", ""Ancalagon"", ""Scolecofurca"", and ""Lecythioscopa"", the organism was originally classified into a clade termed the archaeopriapulida, a stem group to the Priapulids proper. However, the morphological similarity of these organisms to their modern cousins is remarkable, especially"
"superfamily Canoidea (or suborder Caniformia) – Canidae (wolves, dogs and foxes), Mephitidae (skunks and stink badgers), Mustelidae (weasels, badgers, and otters), Procyonidae (raccoons), Ursidae (bears), Ailuridae (red panda), Otariidae (eared seals), Odobenidae (walrus), and Phocidae (earless seals) (the last three families formerly classified in the superfamily Pinnipedia) and the extinct family Amphicyonidae (bear-dogs) – are characterized by having nonchambered or partially chambered auditory bullae, nonretractable claws, and a well-developed baculum. Most species are rather plain in coloration, lacking the flashy spotted or rosetted coats like many species of felids and viverrids have. This is because Canoidea tend to range in"
"seem to make up a monophyletic clade, while the Ophidioidei are oviparous. Ophidiiformes Ophidiiformes is an order of ray-finned fish that includes the cusk-eels (family Ophidiidae), pearlfishes (family Carapidae), viviparous brotulas (family Bythitidae), and others. Members of this order have small heads and long slender bodies. They have either smooth scales or no scales, a long dorsal fin and an anal fin that typically runs into the caudal fin. They mostly come from the tropics and subtropics, and live in both freshwater and marine habitats, including abyssal depths. They have adopted a range of feeding methods and lifestyles, including parasitism."
"Ophiderpeton Ophiderpeton is an extinct genus of lepospondyl amphibian from the early Carboniferous to the early Permian. Remains of this genus are widespread and were found in Ohio, United States and the Czech Republic (Central Europe). An aïstopod, ""Ophiderpeton"" was snake-like, without any trace of limbs. Its body was about long, with 230 vertebrae. The skull measured , and large, forward-facing eyes, suggesting a hunting lifestyle. It probably lived in burrows, feeding on insects, worms, millipedes, and snails. A large number of species are classified in the genus, and similar animals, ""Phlegethontia"" and ""Sillerpeton"", are known. An earlier genus, ""Lethiscus"","
"than three major cladistic branches of placential mammals: Meridiungulata (if xenungulates are the closest relatives), Laurasiatheria (if dinoceratans are the closest relatives) and Afrotheria (if embrithopods are the closest relatives). Pyrotheria Pyrotheria is an order of extinct meridiungulate mammals. These mastodon-like ungulates include the genera ""Baguatherium"", ""Carolozittelia"", ""Colombitherium"", ""Gryphodon"", ""Propyrotherium"", ""Proticia"", and ""Pyrotherium"". They had the appearance of large, digitigrade, tapir-like mammals with relatively short, slender limbs and five-toed feet with broad, flat phalanges. Their fossils are restricted to Paleocene through Oligocene deposits of Brazil, Peru and Argentina. Some experts place the clade Xenungulata (which contains several genera, including ""Carodnia"")"
"""Ophidiaster"" and ""Phataria"" shed single arms that regenerate the disc and the remaining rays to form a complete individual. Some of these also reproduce asexually by parthenogenesis. The name of the family is taken from the genus ""Ophidiaster"", whose limbs are slender, semitubular and serpentine. These genera are accepted in the World Register of Marine Species: Ophidiasteridae The Ophidiasteridae (Greek ""ophidia"", Οφιδια, ""of snakes"", diminutive form) are a family of sea stars with about 30 genera. Occurring both in the Indo-Pacific and Atlantic Oceans, ophidiasterids are greatest in diversity in the Indo-Pacific. Many of the genera in this family exhibit"
"mammals from the Ouled Abdoun come from upper levels of Ypresian age and include ""Phosphatherium"" (Proboscidea), ""Seggeurius"" (Hyracoidea), ""Daouitherium"" (Proboscidea), ""Boualitomus"" (Hyaenodontidae), and a poorly known undetermined species. Among them ""Phosphatherium"" is the best known and most frequent. Mammals are extremely rare in the Ouled Abdoun in contrast to the associated marine vertebrate fauna which includes sea birds, sharks, bony fish, and marine reptiles (including crocodilians, sea turtles, and the sea snake ""Palaeophis""). Terrestrial species were probably transported off shore into the Moroccan sea before fossilization. Ocepeia Ocepeia is an extinct genus of afrotherian mammal that lived in present-day Morocco"
"groups that it is placed in its own family, Ocepeiidae. ""Ocepeia"" lived at a time when northwest Africa was at the intersection of the Atlantic Ocean and the ancient Tethys Ocean, and much of the area was flooded by shallow, warm inland seas. ""Ocepeia"" fossils are associated with diverse sharks, birds, and marine reptiles, and a small number of early mammals, including other condylarths and early proboscideans. The early appearance and specialized features of ""Ocepeia"" suggest afrotherians originated and diversified within Africa, contrary to theories suggesting a more northern origin. All specimens of ""Ocepeia"" come from the Ouled Abdoun Basin"
"Ophidia, or modern snakes. ""Acteosaurus"" is described as slender or snake-like, similar to other dolichosaurids. Its shortened forelimbs and long tail help to distinguish it from other genera, and its vertebral column is similar to more modern varanid lizards. The holotype, when it was discovered, was unfortunately missing its head. So, while Meyer was unable to come up with an exact number, he noted that ""Acteosaurus"" has at least 10 cervical vertebrae, and 27 dorsals. There are small articular processes on the trunk vertebrae, and it has long, narrow neural spines, and posteroventrally positioned, unfused haemal arches on the vertebrae"
"Ferae The Ferae are a clade of mammals, consisting of the orders Carnivora (over 260 species, around the globe) and Pholidota (eight species of pangolins in tropical Africa and Asia). Pangolins do not exhibit morphological traits typically associated with carnivorans (wolves, cats, seals, and so on), and were thought to be the closest relatives of Xenarthra (armadillos and sloths), but DNA research conducted in the 2000s found the close relationship to carnivorans. Several extinct orders, relatives of the Pholidota, such as Creodonts, are members of Ferae as well. An alternate name, Ostentoria, has also been proposed for a grouping of"
"Ophiurida The Ophiurida are an order of echinoderms within the class Ophiuroidea. It includes the vast majority of living brittle stars. Ophiurida have bursae for respiration and excretion, and dorsal and ventral arm shields are present and usually well developed. Arms are unbranched and incapable of coiling vertically. Most are five-armed, some with 4 or 6 arms as an abnormality, but others properly bear six or seven arms. The madreporite is on the oral surface. The digestive glands are entirely within the central disc. They move their arms side to side by means of ball-and-socket joints. Tropical species tend to"
"Ophisaurus Ophisaurus (from the Greek 'snake-lizard') is a genus of reptiles that resemble snakes, but are actually lizards. Although most species have no legs, their head shapes, movable eyelids, and external ear openings identify them as lizards. A few species have very small, stub-like legs near their rear vents. These are vestigial organs, meaning they have evolved and are no longer in use. They reach lengths of up to , but about two-thirds of this is the tail. Glass lizards feed on insects, spiders, other small reptiles, and young rodents. Their diets are limited by their inability to unhinge their"
"Squid Squid are cephalopods in the order Teuthida with elongated bodies, large eyes, eight arms and two tentacles. Like all other cephalopods, squid have a distinct head, bilateral symmetry, and a mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius or pen, made of chitin. Squid can change colour for camouflage and signalling. Some species are bioluminescent, using their light for counter-illumination camouflage. Squid are members of the class Cephalopoda, subclass Coleoidea. The squid orders Myopsida and Oegopsida are in the superorder Decapodiformes (from the Greek for ""ten-legged""). Two"
"Opossum The opossum () is a marsupial of the order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 103 or more species in 19 genera. Opossums originated in South America and entered North America in the Great American Interchange following the connection of the two continents. Their unspecialized biology, flexible diet, and reproductive habits make them successful colonizers and survivors in diverse locations and conditions. The animal is also known as a possum, particularly in North America. The word ""opossum"" is borrowed from the Powhatan language and was first recorded between"
"is known from the Carboniferous and Early Permian. Ophiderpeton Ophiderpeton is an extinct genus of lepospondyl amphibian from the early Carboniferous to the early Permian. Remains of this genus are widespread and were found in Ohio, United States and the Czech Republic (Central Europe). An aïstopod, ""Ophiderpeton"" was snake-like, without any trace of limbs. Its body was about long, with 230 vertebrae. The skull measured , and large, forward-facing eyes, suggesting a hunting lifestyle. It probably lived in burrows, feeding on insects, worms, millipedes, and snails. A large number of species are classified in the genus, and similar animals, ""Phlegethontia"""
"shrimps and crabs such as ""Carcinus maenas"" and ""Liocarcinus depurator"" being prominent. In six hours, little remained except the limbs of crustaceans and the discs of ophiuroids. The crab ""Pagurus bernhardus"" was the most likely scavenger to consume ""O. ophiura"" in baited traps. Ophiura ophiura Ophiura ophiura or the serpent star is a species of brittle star in the order Ophiurida. It is typically found on coastal seabeds around northwestern Europe. ""O. ophiura"" has a circular central disc up to 35 mm (1.5 in) wide and five radially arranged, narrow arms each up to long. The general colour is mottled"
"carrier for arthritis remedies given as topical salves. Opossum pelts have long been part of the fur trade. Classification based on Voss and Jansa (2009) Opossum The opossum () is a marsupial of the order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 103 or more species in 19 genera. Opossums originated in South America and entered North America in the Great American Interchange following the connection of the two continents. Their unspecialized biology, flexible diet, and reproductive habits make them successful colonizers and survivors in diverse locations and conditions. The"
"Giraffidae The Giraffidae are a family of ruminant artiodactyl mammals that share a common ancestor with cervids and bovids. This family, once a diverse group spread throughout Eurasia and Africa, presently comprises only two extant genera, the giraffe (one species of ""Giraffa"") and the okapi (the only known species of ""Okapia""). Both are confined to sub-Saharan Africa: the giraffe to the open savannas, and the okapi to the dense rainforest of the Congo. The two genera look very different on first sight, but share a number of common features, including a long, dark-coloured tongue, lobed canine teeth, and horns covered"
"the fast-moving seven armed starfish (""Luidia ciliaris""). Individuals of this species are either male or female. Fertilisation is external and the larvae are planktonic. It is a fast-growing brittle star and is not thought to live for more than three years. Ophiura albida Ophiura albida is a species of brittle star in the order Ophiurida. It is typically found on the seabed in the north eastern Atlantic Ocean and in the Mediterranean Sea and is sometimes known as the serpent’s table brittle star. ""Ophiura albida"" has a central disc reaching a diameter of about and five arms up to long."
"Pyrotheria Pyrotheria is an order of extinct meridiungulate mammals. These mastodon-like ungulates include the genera ""Baguatherium"", ""Carolozittelia"", ""Colombitherium"", ""Gryphodon"", ""Propyrotherium"", ""Proticia"", and ""Pyrotherium"". They had the appearance of large, digitigrade, tapir-like mammals with relatively short, slender limbs and five-toed feet with broad, flat phalanges. Their fossils are restricted to Paleocene through Oligocene deposits of Brazil, Peru and Argentina. Some experts place the clade Xenungulata (which contains several genera, including ""Carodnia"") within Pyrotheria, even when dentition, although bilofodont in both orders, is very different. For most scholars, the two orders remain separated. The dentition is complete with strong, procumbent, chisel-shaped incisors,"
"Olbitherium Olbitherium is an extinct mammal of the order Perissodactyla (an early ancestor of modern-day horses, rhinos, and tapirs) from the early Eocene epoch of Shandong, China. ""Olbitherium"" was originally described from lower and upper jaw fragments and several teeth found in the Wutu Formation of Shandong Province. The limited material of ""Olbitherium"" shares similarities with several ungulate groups. According to Tong ""et al."", the upper cheek teeth show similarities to early Perissodactyls, as well as the hyracoid ""Seggeurius"", while the lower cheek teeth more closely resemble those of phenacodontids, such as ""Ectocion"", ""Phenacodus"", and ""Copecion"". Due to these conflicting"
"Eosuchia Eosuchians are an extinct order of diapsid reptiles. Depending on which taxa are included the order may have ranged from the late Carboniferous to the Eocene but the consensus is that eosuchians are confined to the Permian and Triassic. Eosuchia was initially defined to include all ""thecodontian"" reptiles which did not have an antorbital fenestra but did retain tabulars, postparietals and a large pineal foramen (Broom, 1914). Broom coined the term as a new suborder for ""Youngina"". A definition for inclusion in the order is difficult: it is almost easier to list the primitively-diapsid reptiles that have not been"
"animals were included under the order Cotylosauria, and were considered the most primitive and ancestral lineage of reptiles. More recently they have been reclassified as amphibian-grade tetrapods, closely related to the first true amniotes (though they have also been argued to be amniotes more closely related to synapsids than to sauropsids). Contrary to other Reptiliomorph amphibians, the teeth of the Diadectomorpha lacked the infolding of the dentine and enamel that account for the name Labyrinthodontia for the non-amniote tetrapods. Diadectomorpha is most commonly given the rank of order when formal taxonomic ranks are applied. It is further divided into three"
"50 kinds. The egg-bearing tetrapods, ""Ōiotoka tetrapoda"" (reptiles and amphibians) had blood and four legs, but were cold and laid eggs, so were a distinct group. The snakes, ""Opheis"", similarly had blood, but no legs, and laid dry eggs, so were a separate group. The fishes, ""Ikhthyes"", had blood but no legs, and laid wet eggs, forming a definite group. Among them, the selachians ""Selakhē"" (sharks and rays), had cartilages instead of bones. Animals without blood were divided into soft-shelled ""Malakostraka"" (crabs, lobsters, and shrimps); hard-shelled ""Ostrakoderma"" (gastropods and bivalves); soft-bodied ""Malakia"" (cephalopods); and divisible animals ""Entoma"" (insects, spiders, scorpions,"
"classes of reptiles, amphibians, birds, and mammals. The British anatomist Thomas Henry Huxley made Latreille's definition popular and, together with Richard Owen, expanded Reptilia to include the various fossil ""antediluvian monsters"", including dinosaurs and the mammal-like (synapsid) ""Dicynodon"" he helped describe. This was not the only possible classification scheme: In the Hunterian lectures delivered at the Royal College of Surgeons in 1863, Huxley grouped the vertebrates into mammals, sauroids, and ichthyoids (the latter containing the fishes and amphibians). He subsequently proposed the names of Sauropsida and Ichthyopsida for the latter two groups. In 1866, Haeckel demonstrated that vertebrates could be"